Andrea Righi – LinuxDay 2007 (Oct 27) Installare GNU/Linux su un ampio numero di client con SystemImager e BitTorrent Andrea Righi

Andrea Righi – LinuxDay 2007 (Oct 27) The problem You have to install a huge number of computers: ✔ PC labs, ✔ Server farms, ✔ HPC clusters, ✔ Complex grid-computing environments, ✔ Etc. But you don't have enough time!

Andrea Righi – LinuxDay 2007 (Oct 27) Some practical examples

Andrea Righi – LinuxDay 2007 (Oct 27) The tool SystemImager is a software which automates GNU/Linux installs, software distributions and production deployment

Andrea Righi – LinuxDay 2007 (Oct 27) Major Goals Support all Linux distributions Support a large number of architectures Make it solve massive installation problems Create a centralized point of installation and maintenance

Andrea Righi – LinuxDay 2007 (Oct 27) What does it do for me? System Installation System Updates Build replicants of machines File system or block device migration

Andrea Righi – LinuxDay 2007 (Oct 27) Advantage of SystemImager It's open-source (GNU GPL v2) File-oriented approach: ✔ Distribution agnostic ✔ Hardware independence ✔ Filesystem independence ✔ Plain filesystem dump: exclude swap space or unused partitions ✔ Block device independence ✔ Live customization (manipulate cloned filesystems directly)

Andrea Righi – LinuxDay 2007 (Oct 27) Basic concepts

Andrea Righi – LinuxDay 2007 (Oct 27) Basic concept: image Image: ✔ Live snapshot of a machine containing files and directories from the root of that machine's filesystem ✔ chroot-able filesystem stored in /var/lib/systemimager/images/$NAME ✔ Examples: ✔ /var/lib/systemimager/images/RHEL4 ✔ /var/lib/systemimager/images/Ubuntu_gutsy ✔ /var/lib/systemimager/images/HPC_1.0 ✔...

Andrea Righi – LinuxDay 2007 (Oct 27) Basic concept: image server Image Server: ✔ a server that has all the images available for the installation ✔ “Jukebox” of images

Andrea Righi – LinuxDay 2007 (Oct 27) Basic concept: client Client: ✔ a machine to be auto-installed with a (single) pre- selected image ✔ Example: the dancing penguins are the clients :-)

Andrea Righi – LinuxDay 2007 (Oct 27) Basic concept: transport Transport: ✔ the protocol used to distribute images from the image server to the clients ✔ push/pull/p2p approach ✔ Examples: ✔ rsync, multicast, SSL, BitTorrent,...

Andrea Righi – LinuxDay 2007 (Oct 27) Application stack (SIS => SystemImager) Image Server (SystemImager) HPC clusters HA- clusters Web farms PC labs Clients

Andrea Righi – LinuxDay 2007 (Oct 27) Application stack (SIS => SystemImager) Image Server (SystemImager) Golden client HPC clusters HA- clusters Web farms PC labs Software (Debootstrap, YaST, yum, SystemInstaller,...) Clients

Andrea Righi – LinuxDay 2007 (Oct 27) Application stack (SIS => SystemImager) Image Server (SystemImager) Golden client HPC clusters HA- clusters Web farms PC labs Software (Debootstrap, YaST, yum, SystemInstaller,...) Clients RHEL4 HPC- 1.0 SUSE1 0 Debian 4

Andrea Righi – LinuxDay 2007 (Oct 27) Application stack (SIS => SystemImager) Image Server (SystemImager) Golden client HPC clusters HA- clusters Web farms PC labs Software (Debootstrap, YaST, yum, SystemInstaller,...) Clients RHEL4 HPC- 1.0 SUSE1 0 Debian 4 SystemImager transports + SystemConfigurato r

Andrea Righi – LinuxDay 2007 (Oct 27) Application stack (SIS => SystemImager) Image Server (SystemImager) Golden client HPC clusters HA- clusters Web farms PC labs Software (Debootstrap, YaST, yum, SystemInstaller,...) Clients RHEL4 HPC- 1.0 SUSE1 0 Debian 4 SystemImager transports + SystemConfigurato r

Andrea Righi – LinuxDay 2007 (Oct 27) Transports

Andrea Righi – LinuxDay 2007 (Oct 27) rsync transport rsync (plain / SSL encrypted): ✔ Client-server approach ✔ Limited in scalability ✔ Limited in reliability with a lot of clients ✔ Max Theoretical Bandwidth: Us / N

Andrea Righi – LinuxDay 2007 (Oct 27) rsync diagram Image server Client 1 Client 2 Client N... Upload bandwidth = U s Download bandwidth = U s / N

Andrea Righi – LinuxDay 2007 (Oct 27) Multicast (Flamethrower) transport Flamethrower: ✔ Multicast approach: ✔ Perfect scalability ✔ But limited in reliability ✔ Max Theoretical Bandwidth: Us

Andrea Righi – LinuxDay 2007 (Oct 27) Multicast (Flamethrower) diagram Image server Client 1 Client 2 Client N... Upload bandwidth = U s Download bandwidth = U s

Andrea Righi – LinuxDay 2007 (Oct 27) BitTorrent overview BitTorrent is a TCP/IP p2p oriented protocol designed for transferring files Peers connect to each other directly to send and receive chunks of data There is a central server (tracker) which coordinates the action of all such peers The tracker does not have any knowledge of the contents of the files being distributed Users upload (transmit outbound) at the same time they are downloading (receiving inbound)

Andrea Righi – LinuxDay 2007 (Oct 27) BitTorrent transport BitTorrent: ✔ p2p approach: scalability && reliability ✔ Qiu and Srikant model ✔ Total upload rate: ✔ Steady state: ✔ x(t) downloaders => ✔ y(t) uploaders => ✔ Max Theoretical Bandwidth: ✔ Us (steady state)

Andrea Righi – LinuxDay 2007 (Oct 27) BitTorrent diagram Image server (+tracker) Client 1 Client 2 Client N... Upload bandwidth = U s Download bandwidth = U s (in steady state)

Andrea Righi – LinuxDay 2007 (Oct 27) Testbed environment

Andrea Righi – LinuxDay 2007 (Oct 27) BCX/5120 IBM BCX/5120, with 5120 cores, is the largest computer in Italy for Scientific Computing 2 dual-core AMD Opteron(tm) 2.4GHz, 8GB RAM per node It is the 44th most powerful computer in the world (TOP500).

Andrea Righi – LinuxDay 2007 (Oct 27) BCX network topology Cisco Catalyst 6513 IBM Bladecenter H (from 1 up to 11) IBM LS21 switch IBM Blade LS21 (x 14) BladeCenter H internal bus (1Gb/s) Gb/s x 4 uplinks IBM e326m (image server) 1 Gb/s link

Andrea Righi – LinuxDay 2007 (Oct 27) Experimental results

Andrea Righi – LinuxDay 2007 (Oct 27) Deployment time

Andrea Righi – LinuxDay 2007 (Oct 27) Rsync: 50 clients (download rate)

Andrea Righi – LinuxDay 2007 (Oct 27) Multicast: 50 clients (download rate)

Andrea Righi – LinuxDay 2007 (Oct 27) BitTorrent: 50 clients (download rate)

Andrea Righi – LinuxDay 2007 (Oct 27) Rsync: 50 clients (aggregated bandwidth)

Andrea Righi – LinuxDay 2007 (Oct 27) Multicast: 50 clients (aggregated bandwidth)

Andrea Righi – LinuxDay 2007 (Oct 27) BitTorrent: 50 clients (aggregated bandwidth)

Andrea Righi – LinuxDay 2007 (Oct 27) Conclusion

Andrea Righi – LinuxDay 2007 (Oct 27) Advantages Quicker deployment of images Safer deployment (better error handling) Less load on the image server ✔ no need to buy a powerful machine

Andrea Righi – LinuxDay 2007 (Oct 27) Disadvantages More disk space consumption! ✔ images + tarballs of images Images and tarballs must be kept in-sync ✔ Re-generate tarball and.torrent at each image change

Andrea Righi – LinuxDay 2007 (Oct 27) Future work Improve security (encryption of BT tarballs) Exploit the p2p approach to create distributed and redundant repositories of custom image Virtual cluster deployment (re-imaging using the same physical resource pool) Use BT transport also for updates (pushing changes/differences of images)

Andrea Righi – LinuxDay 2007 (Oct 27) References Web: ✔ Mailing list: ✔ ✔ IRC: ✔ #sisuite (irc.freenode.net)

Andrea Righi – LinuxDay 2007 (Oct 27) Tank you for attending